Small diameter horizontal tunneling machine

ABSTRACT

A method and apparatus for continuously drilling and lining a small diameter horizontal tunnel are disclosed. A head assembly of the tunneling machine includes a support section and a rotatable section which is rotatably journaled on the support section. The rotatable section includes at least one roller cutter which engages the end face of the tunnel for removing material from the end face. A rotatable drive shaft extends through the tunnel and is connected to the rotatable section for providing the sole means for rotating the rotatable section. A thrust unit at the portal of the tunnel is connected to the tunnel liner and applies a force solely through the tunnel liner to axially advance the head assembly.

I United States Patent 1 Fink [52] US. Cl. 175/73; 175/62; 175/171;175/334; 175/336 [51] Int. Cl. E21B 7/04; E21B 9/34; E21B 3/02 [58]Field of Search 175/62, 162, 73, 334, 171, 175/336; 299/55, 31, 33, 56,57; 61/85 [56] References Cited UNITED STATES PATENTS 2,625,375 1/1953Hall 175/171 X 2,675,213 4/1954 Poole et al. 175/171 X 3,098,534 7/1963Carr et a1 175/73 3,196,959 7/1965 Kammerer 175/73 3,612,195 10/1971Richmond 175/171 X Nov. 4, 1975 3,767,836 10/1973 Geis et a1 175/62 XPrimary Examiner-Stephen J. Novosad Attorney, Agent, or FirmMcNenny,Farrington, Pearne & Gordon [57] ABSTRACT A method and apparatus forcontinuously drilling and lining a small diameter horizontal tunnel aredisclosed. A head assembly of the tunneling machine includes a supportsection and a rotatable section which is rotatably journaled on thesupport section. The rotatable section includes at least one rollercutter which engages the end face of the tunnel for removing materialfrom the end face. A rotatable drive shaft extends through the tunneland is connected to the rotatable section for providing the sole meansfor rotating the rotatable section. A thrust unit at the portal of thetunnel is connected to the tunnel liner and applies a force solelythrough the tunnel liner to axially advance the head assembly.

8 Claims, 6 Drawing Figures U.S. Patent NOV.4, 1975 Sheet10f3 3,917,010

US. Patent Nov. 4, 1975 Sheet2 of3 3,917,010

US. Patent Nov. 4, 1975 Sheet 3 of 3 3,917,010

SMALL DIAMETER HORIZONTAL TUNNELING MACHINE BACKGROUND AND SUMMARY OFTHE INVENTION Small diameter horizontal tunneling machines are used fordrilling or boring tunnels less than feet in diameter through varioustypes of earth formations. Such machines are used where it is eitherimpractical or impossible to excavate a trench from the surface of theground, such as when drilling through hills or mountains or whendrilling transversely beneath highways.

Commercially used prior art tunneling machines for such purposes includean auger which carries materials from the end face of the tunnel to theportal of the tunnel, and teeth or scrapers which are mounted on the endof the auger and are rotated by the auger and pushed by the augeragainst the end face of the tunnel. A cylindrical tunnel liner is alsoinserted into the tunnel as it is being drilled, and the auger rotatesinside the tunnel liner. A dieselengine powered hydraulic thrust unit islocated at the portal of the tunnel to provide, the force to rotate andpush the auger with its associated teeth or scrapers during drilling andto push the tunnel liner into the tunnel. The entire axial force to pushthe teeth or scrapers against the tunnel end face as they are beingrotated is applied through the auger, and there is no mechanicalconnection between the teeth or scrapers and the tunnel liner. Theseprior art machines are available from Richmond Manufacturing Co., P.O.Box 188, Ashland, Ohio 44805, USA.

Other tunneling machines include those shown in US. Pat. Nos. 3,763,657to Colson and 3,778,107 to I-Iaspert. Devices for steering prior arttunneling machines are shown in US. Pat. Nos. 3,413,033 to Clark,3,411,826 to Wallers, and 3,382,002 to Tabor.

The present invention improves over these prior art methods and machinesby providing a method and apparatus in which a force applied axially tothe tunnel liner at the portal provides the sole force for axiallyadvancing the cutter head, while the auger rotates the cutter head.

According to the principles of the invention, a head assembly includes asupport section and a rotatable section rotatably journaled on thesupport section. The rotatable section includes at least one rollercutter, and an auger is connected to the rotatable section for providingthe sole means for rotating it. A thrust unit at the tunnel portal isconnected to the tunnel liner and applies a force solely through thetunnel liner to axially advance the head assembly. The support sectionincludes a radially outer ring, a radially inner hub, and at least twospokes fixedly connecting the inner hub to the outer ring. Steeringwedges are located on the outer ring at the location of the spokes, andthe space between the spokes is open so that material removed from thetunnel end face is transmitted rearwardly to the portal of the tunnelthrough the space between the spokes.

shown in the drawingsywherein:

FIG. 1' is a'perspective view of a head assembly according to theprinciples of the invention;

FIG. 2 is a schematic side elevational view showing the head assembly ofFIG. 1 being pushed against a tunnel end face by a thrust unit;

FIG. 3 is a cross-sectional side elevational view of the head assemblyand tunnel liner and auger, but with the roller cutters and scrapersremoved from the head assembly;

FIG. 4 is a rear view of the head assembly shown in FIG. 1;

FIG. 5 is a cross-sectional view of a steering wedge for the headassembly taken along reference view line 5-5 of FIG. 4; and

FIG. 6 is a cross-sectional view of the steering wedge taken alongreference view line 6-6 of FIG. 5.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings ingreater detail, FIG. 1 shows a head assembly 11 according to theprinciples of the invention. The head assembly 11 includes a supportsection 12 and a rotatable section 13 which is rotatably journaled onthe support section 12. As will be explained in greater detail below,the support section 12 includes a radially outer ring 15, a radiallyinner hub 16, and four spokes l7, 18, I9 and 20 (only one of which maybe seen in FIG. 1) fixedly connecting the inner hub 16 to the outer ring15. I

The rotatable section 13 of the head assembly 11 includes a generallyflat mounting plate 23 which has secured thereto in a suitable mannersuch as by welding or by bolting two gage or outside roller cutters 24and 26 and two inside roller cutters 25 and 27. Each of the cutters24-27 is journaled on the mounting plate 23 for rotational movement, andeach of the cutters 24-27 engages the end face of the tunnel withrolling contact to remove materials therefrom.

Still referring to FIG. 1, two material deflector carriers 30 and 31 arealso welded to the mounting plate 23, and each of the deflector carriers30 and 31 is provided with a suitable reinforcing rib to prevent bendingor breakage. A material deflector 32 is bolted to each of the deflectorcarriers 30 and 31. As the rotatable section 13 rotates, the deflectors32 deflect materials which are removed from the end face of the tunnelby the cutters 24-27 axially rearwardly through the spaces between thespokes 17-20 so that such materials can be removed from the tunnel. Whenthe deflectors 32 become worn, they may be removed from their carriers30 and 31 for replacement.

Referring now to FIG. 2, the tunneling machine including the headassembly 11 shown in FIG. I is illustrated schematically in relation toan earth formation 36.which may include hard rock through which a tunnelis to be drilled or bored. The head assembly 11 is bolted in a mannerdescribed below to a multiple section tunnel liner 37. The tunnel liner37, in a wellknown manner, is a cylindrical steel pipe which is providedin relatively short lengths which are welded together to increase thelength of the liner 37 as the tunnel progresses into the earth formation36. A diesel engine powered hydraulic thrust unit 38 is also provided atthe portal of the tunnel for axially advancing the tunnel liner 37 andfor rotating a drive shaft 39 which extends axially through the tunnelliner 37. As described in detail below, the drive shaft 39 isoperatively connected to the head assembly 11 for providing the solemeans for rotating the rotatable section 13. The thrust unit 38 ismovable back and forth along a suitable base 40 for axially advancingthe tunnel liner 37 as the tunnel progresses. When the thrust unit 38approaches the portal of the tunnel, it is moved back along the base 40away from the portal and a new section of the tunnel liner 37 is weldedin place to extend the length of the tunnel liner 37. A new section ofdrive shaft 39 is also added to extend the length of the drive shaft 39.The thrust unit 38 is then advanced again toward the portal of thetunnel to further advance the tunnel liner 37 and head assembly 11. Thestructure of the thrust unit 38 is well-known in the art, and suitablethrust units are available from Richmond Manufacturing Co., PO. Box 188,Ashland, Ohio 44805, U.S.A.

Turning now to FIG. 3, the structural details of the head assembly 11and drive shaft 39 and liner 37 are shown in detail. For purposes ofclarity, the roller cutters 24-27, deflector carriers 30 and 31, anddeflectors 32 have been removed from the mounting plate in FIG. 3. Thedrive shaft 39 includes an auger which conveys materials from the headassembly 11 to the tunnel portal for removal. The drive shaft 39 is amultiple section drive shaft which is made in short lengths which aresecured together to lengthen the drive shaft as the tunnel progresses,as described below.

Referring still to FIG. 3, an annular adapter ring 47 is welded to thefree end of the tunnel liner 37 (that is, the end of the tunnel liner 37away from the thrust unit 38), and the adapter ring 47 is bolted by aplurality of circumferentially spaced bolts 48 to the ring tomechanically connect the head assembly 11 to the tunnel liner 37.

The hub 16 includes a forward bearing retainer 49 for securing the outerrace of a roller thrust bearing 51 against movement relative to the hub16 and a seal retainer 50. The rotatable section 13 includes an axleportion 55, and a bearing retainer 56 secures the inner race of thebearing 51 on the axle portion 55. Although the mounting plate 23 andaxle portion 55 are shown as a single piece in FIG. 3 for purposes ofclarity, these parts of the rotatable section 13 are preferably made ofseparate pieces which are welded together. In this manner, the rotatablesection 13 is journaled on the support section 12 for rotationalmovement relative thereto by the bearing 51 which transmits axial forcesbetween the support section 12 and the rotatable section 13.

A passage 57 extends from end to end through the mounting plate 23 andaxle portion 55. The passage 57 is of hexagonal lateral cross-section,and a hexagonal end portion 58 of the drive shaft' 39 is received withinthe passage 57 so that rotation of the drive shaft 39 rotates therotatable section 13. Although the thrust unit 38 advances both theliner 37 and drive shaft 39 as it moves toward the tunnel portal, thedrive shaft 39 does not transmit a force in the axial direction from thethrust unit 38 to the movable section 13. This is because the driveshaft 39 is dimensioned axially so that it cannot simultaneously axiallyengage both the thrust unit 38 and the rotatable section 13. This isaccomplished by providing a gap 59 between shoulder 59a on drive shaft39 and end face 54 on axle portion 55. In this manner, the entire axialforce applied to axially advance the rotatable section 13 is applied tothe end of the tunnel liner 37 at the portal, and excessive axial forceson the drive shaft 39 that might bend or break the drive shaft 39 areavoided.

Referring now to FIGS. 3 and 4, it is seen that the four spokes, 17, 18,19 and are equally spaced apart about the ring 15 and hub 16. A steeringwedge 60 is secured on the head assembly 11 in axially aligned relationto each of the spokes 17, 18, 19 and 20 to steer the head assembly 1 1as the tunnel is cut. This arrangement leaves the spaces between thespokes 20 and 17 and between the spokes 17 and 18 and between the spokesl8 and '19 unobstructed for the passage of material through such spacefor removal from the tunnel. A U- shaped channel 61 extends from theouter ring 15 to the hub 16 to convey hydraulic fluid from fourhydraulic lines 63 (only one of which is shown inFIG. 3) on the outersurface of the tunnel liner 37 to each of the steering wedges 60. Ifdesired, a suitable cover or enclosure can be provided for the hydrauliclines 63 on the outer surface of the tunnel liner 37 to prevent damageto the lines 63. The U-shaped channel 61 includes suitable passagesdrilled in its sides, and the hydraulic lines 63 are each connected tothe portion of the channel 61 adjacent the outer ring 15 while otherhydraulic hoses 62 are connected to the passages in the channel 61 forconnection to the steering wedges 60. As shown in FIG. 4, each of thesteering wedges 60 is provided with a separate hydraulic hose 62 so thatthe steering wedges 60 are each individually actuatable.

As best seen in FIG. 5, each steering wedge 60 includes a cylindermounting bracket 65 which is bolted to its associated spoke, which isthe spoke 17 for the steering wedge 60 shown in FIG. 5. A suitable cover66 is bolted to the cylinder mounting bracket 65 to protect the steeringwedge 60 from foreign materials. The steering wedge 60 also includes asingle acting spring returned hydraulic cylinder 67 having a rod 68pivotally connected to a steering shoe 69 at a pivot 70. The other endof the steering shoe 69 is connected to the cylinder mounting bracket 65at another pivot 71. When the cylinder 67 is in its deactuated or springreturned position shown by solid lines in FIG. 5, the steering shoe 69is in its retracted position so that it does not project beyond theouter peripheral surface of the ring 15. When hydraulic fluid issupplied to the cylinder 67, the rod 68 pushes the shoe 69 to itsactuated position shown in phantom in FIG. 5 to steer the head assembly11 as the tunnel is drilled.

The manner of supporting the cylinder 67 is best shown in FIG. 6.Cylinder trunnions 64 are secured to the cylinder 67 by welding or by asuitable bracket (not shown) and are retained on the cylinder mountingbracket 65 by trunnion caps 72. This pivotal mounting of the cylinder 67on the mounting bracket 65 permits the cylinder 67 to rotate slightlywhen the shoe 69 moves between its retracted position and its extendedposition to accommodate movement of the pivot point 70 as shown in FIG.5.

Turning now to the operation of the tunneling.machine shown in thedrawings, the thrust unit 38 including the support 40 is installed in awell-known manner with the thrust unit 38 in its start-up positionspaced away from the portal of the tunnel to be drilled as shown in FIG.2. The head assembly 11 is bolted to the adapter ring 47 on the free endof the tunnel liner 37, and the drive shaft 39 with its associated augerare rotated by the thrust unit 38. The thrust unit 38 then moves totheleft as shown in FIG. 2 applying an axial force to the tunnel liner37 to urge the roller cutters of the head assembly 11 againstthe earthformation 36 including the hard rock through which the tunnel is to bedrilled. Because the drive shaft 39 is dimensioned as explained above sothat it can transmit only rotational forces between the thrust unit 38and the head assembly 11, the drive shaft 39 cannot be deflected anddamaged by application of an axial thrust by the thrust unit 38exceeding the column strength of the drive shaft 39. After the thrustunit 38 advances to the left as shown in FIG. 2 to a position adjacentthe tunnel portal at the end of the support track 40, the thrust unit 38is retracted to the right as viewed in FIG. 2 away from the tunnelportal while the drive shaft 39 and tunnel liner 37 remain stationary. Anew length of drive shaft 39 with its associated auger and a new lengthof tunnel liner 37 are then secured on the end of the drive shaft 39 andtunnel liner 37 adjacent the thrust unit 38, and the operation isrepeated.

When the tunnel is completed, the head assembly 11 breaks through theother side of the earth formation 36 (not shown). The head assembly 11is removed from the tunnel liner 37 by removing the bolts 48 (FIG. 3),the drive shaft 39 is removed, and the hydraulic lines 63 are removed.The tunnel liner 37 is left in place to provide a permanent liner forthe tunnel.

What is claimed is:

1. In combination, a tunnel having an end face and a portal, and atunneling machine; said tunneling machine comprising a head assembly, amultiple section tunnel liner, a multiple section rotatable drive shaft,and axial thrust unit means; said head assembly including a supportsection movable in said tunnel in the axial direction and a rotatablesection movable in said tunnel in both the axial and the rotationaldirections, said rotatable section including cutter means for engagingsaid end face of said tunnel for removing material from said end face,said rotatable section being rotatably journaled on said support sectionby bearing means, said bearing means preventing relative axial movementbetween said rotatable section and said support section whereby axiallyadvancing movement of said support section axially advances. saidmovable section; said rotatable drive shaft being operatively connectedto said rotatable section and providing the sole means for rotating saidrotatable section; said thrust unit means being disposed outside of saidtunnel at said portal, said thrust unit means being operativelyconnected to said tunnel liner and said tunnel liner being operativelyconnected to said support section, and said thrust unit means axiallyadvancing said support section and said rotatable section together insaid tunnel by application of an axial force to the end of said tunnelliner at said portal.

2. The combination defined in claim 1 wherein said cutter means includesat least one roller cutter engaging said end face of said tunnel withrolling contact.

3. The combination defined in claim 1 wherein said thrust unit providesthe sole means for axially advancing said support section and saidrotatable section to gether in said tunnel by application of said axialforce to said end of said tunnel liner at said portal.

4. The combination defined in claim 1 wherein said support sectionincludes a radially outer ring operatively connected to said liner, aradially inner hub, a plurality of spokes fixedly connecting said innerhub to said outer ring, and the space between said spokes being openalong the entire axial extent of said spokes whereby said materialremoved from said tunnel end face by said cutter means is transmittedthrough said space.

5. The combination defined in claim 4 wherein said movable sectionincludes at least one deflector for defleeting said materials axiallyrearwardly as said movable section is rotated by said drive shaft.

6. The combination defined in claim 5 wherein said drive shaft includesan auger extending from the portion of said liner adjacent said supportsection axially rearwardly to the portion of said liner adjacent saidthrust unit for conveying said material out of said tunme].

7. The combination defined in claim 6 wherein said outer ring includesat least two steering wedges, said steering wedges are hydraulicallyactuatable for steering said tunneling machine, at least one hydraulicline supplies fluid for actuating said steering wedge, and saidhydraulic line extends along the outer peripheral surface of said linerbetween said liner and said tunnel.

8. The combination defined in claim 6 wherein said outer ring includesat least two steering wedges, said steering wedges are hydraulicallyactuatable for steering said tunneling machine, and each of saidsteering wedges is disposed in axially aligned relation with one of saidspokes between said spokes and said portal whereby said steering wedgesdo not interfere with the flow of material through said space.

1. In combination, a tunnel having an end face and a portal, and atunneling machine; said tunneling machine comprising a head assembly, amultiple section tunnel liner, a multiple section rotatable drive shaft,and axial thrust unit means; said head assembly including a supportsection movable in said tunnel in the axial direction and a rotatablesection movable in said tunnel in both the axial and the rotationaldirections, said rotatable section including cutter means for engagingsaid end face of said tunnel for removing material from said end face,said rotatable section being rotatably journaled on said support sectionby bearing means, said bearing means preventing relative axial movementbetween said rotatable section and said support section whereby axiallyadvancing movement of said support section axially advances said movablesection; said rotatable drive shaft being operatively connected to saidrotatable section and providing the sole means for rotating saidrotatable section; said thrust unit means being disposed outside of saidtunnel at said portal, said thrust unit means being operativelyconnected to said tunnel liner and said tunnel liner being operativelyconnected to said support section, and said thrust unit means axiallyadvancing said support section and said rotatable section together insaid tunnel by application of an axial force to the end of said tunnelliner at said portal.
 2. The combination defined in claim 1 wherein saidcutter means includes at least one roller cutter engaging said end faceof said tunnel with rolling contact.
 3. The combination defined in claim1 wherein said thrust unit provides the sole means for axially advancingsaid support section and said rotatable section together in said tunnelby application of said axial force to said end of said tunnel liner atsaid portal.
 4. The combination defined in claim 1 wherein said supportsection includes a radially outer ring operatively connected to saidliner, a radially inner hub, a plurality of spokes fixedly connectingsaid inner hub to said outer ring, and the space between said spokesbeing open along the entire axial extent of said spokes whereby saidmaterial removed from said tunnel end face by said cutter means istransmitted through said space.
 5. The combination defined in claim 4wherein said movable section includes at least one deflector fordeflecting said materials axially rearwardly as said movable section isrotated by said drive shaft.
 6. The combination defined in claim 5wherein said drive shaft includes an auger extending from the portion ofsaid liner adjacent said support section axially rearwardly to theportion of said liner adjacent said thrust unit for conveying saidmaterial out of said tunnel.
 7. The combination defined in claim 6wherein said outer ring includes at least two steering wedges, saidsteering wedges are hydraulically actuatable for steering said tunnelingmachine, at least one hydraulic line supplies fluid for actuating saidsteering wedge, and said hydraulic line extends along the outerperipheral surface of said liner between said liner and said tunnel. 8.The combination defined in claim 6 wherein said outer ring includes atleast two steering wedges, said steering wedges are hydraulicallyactuatable for steering said tunneling machine, and each of saidsteering wedges is disposed in axially aligned relation with one of saidspokes between said spokes and said portal whereby said steering wedgesdo not interfere with the flow of material through said space.